HOMESTEAD, Fla.—With a car capable of winning and Brad Keselowski having problems, everything went according to plan for Jimmie Johnson for the first 212 laps of the season finale Sunday at Homestead-Miami Speedway.

But then the day turned soured for the five-time Sprint Cup champion.

Johnson pitted for what was supposed to be his last stop of the day and the crew failed to get all five lug nuts on the left front tire and Johnson had to pit again. That dropped him to 25th, one lap down, and put his comeback hopes in jeopardy on a day when he had to make up 20 points on Keselowski.

Then it got even worse. Johnson felt a vibration and he could smell what he thought was a burning gear. He pulled into the garage for the final 43 laps, with a possible hole in an oil line.

His day was over as he settled for a 36th-place finish and dropped to third in the standings, 40 points behind Keselowski, the new series champion.

“We had 80 percent of the Chase that we needed to have,” said Johnson, who had the points lead before crashing last week at Phoenix. “So it’s hard to be real down on myself or real down on where we finished.

“These championships are special, and it takes an entire 10 races—clean 10 races to win one of these things.”

Initially he thought Keselowski had finished 21st—“I about lost my lunch,” he said. Keselowski actually finished 15th, meaning that even if Johnson had won the race (and Keselowski finished 16th), Keselowski still would have won the title.

“I would have hated to have come out here and do the trash talking I did all week and run 25th all night long,” said Johnson, who led 25 laps. “I’m proud of the fact that we went out there and backed up what we said we could do and we put the pressure on them.

“It doesn’t take the sting away from the championship but (having a mechanical failure) helps in some ways and stings in others.”

Having something that wasn’t a driving mistake made Johnson feel a bit better but he likely will wonder what he could have done if he had been leading the race near the finish to put pressure on Keselowski.

“We would have made it really interesting at the end of this thing if we didn’t have the mistake on pit road and the gear failure at the end,” Johnson said.

That mistake is something that typically doesn’t happen to Johnson and his Hendrick Motorsports team.

“I was eerily calm for whatever reason,” Johnson said about his reaction to the missing lug nut. “(I) flat-lined. (We put) the lug nut on, came back out and then we had our other problem.”

Even though the team had no shot at the title, it tried to repair the car throughout the final 43 laps.

“Our troubles were pretty big, and there weren't many laps left,” Johnson said.

“It was more about going through the motions and trying from a pride standpoint to get out on the track and run the final lap of the season.”

Team owner Rick Hendrick said mistakes and broken pieces happen, and all the team can do is make sure it does its best to correct any mistakes.

“A pinhole in a line—something hit it or I don’t know (exactly) how it happened,” Hendrick said. “We had to run a bunch of perfect races to win five (titles) in a row. … This Chase setting we have with points as tight as they are, you just can’t have a problem.

“I know it wasn’t from a lack of effort. We had a lug nut start it and then we had a hole in the line and that’s just racing. If you let that destroy you, you will never be able to win again.”